that within the next two centuries we will be unable to
maintain this civilization unless we get new sources of certain basic
raw materials?

"But we have one other chance now. The solution is--there are nine
planets in this solar system! Neptune and Uranus are each far vaster
than Earth; they are utterly impossible for life as we know it, but a
small colony might be established there to refine metals for the distant
Earth. We might be able to build domed and sealed cities. But first we
could try the nearer planets--Mars, Venus, or some satellites such as
our Moon. I certainly hope that this machine will make it possible."

For some time they sat in silence as they sped along, high above the
green plains of Indiana. Chicago lay like some tremendous jewel far off
on the horizon to the right and ahead. Five miles below them the huge
bulk of the Transcontinental plane seemed a toy as it swung slowly
across the fields--actually traveling over six hundred miles an hour.
At last Morey spoke.

"You're right, Arcot. We'll have to think of the interplanetary aspects
of this some day. Oh, there's Chicago! We'd better start the vacuum gas
protector. And the radar. We may soon see some action."

The three men immediately forgot the somewhat distant danger of the
metal shortage. There were a number of adjustments to be made, and these
were quickly completed, while the machine forged evenly, steadily ahead.
The generator was adjusted to maximum efficiency, and the various tubes
were tested separately, for though they were all new, and each good for
twenty-five thousand hours, it would be inconvenient, to say the least,
if one failed while they were in action. Each tested perfect; and they
knew from the smooth functioning of the various relays that governed the
generator, as the loads on it varied, that it must be working perfectly,
at something less than one-half maximum rating.

Steadily they flew on, waiting tensely for the first sign of a glow from
the tiny neon tube indicator on the panel before Morey.

"This looks familiar, Dick," said Morey, looking about at the fields and
the low line of the blue mountains far off on the western horizon. "I
think it was about here that we took our little nap in the 'Flying Wheel
chair', as the papers called it. It would be about here th-- LOOK! It is
about here! Get ready for action, Fuller. You're taking the machine gun,
I'll work the invisibility disrupter, and Arcot will run the ship.